We have an issue with a device on a route receiving TCP resets whenever a connection is attempted. This route goes through a third party. We have removed all blocks on our part of the network. My question is, how do access-lists deal with denied packets. Do they direct the packet to Null0 and simply drop the packet or would an extended access-list denying on a TCP rule send a reset thereby closing the connection? My own feeling is that there may be a firewall rule in the way as the reset is at layer 4. Would apprecieate some clarification.